main.c

this is source code of arm9

/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support  -  ROUSSET  -
 * ----------------------------------------------------------------------------
 * Copyright (c) 2006, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaiimer below.
 *
 * - Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the disclaimer below in the documentation and/or
 * other materials provided with the distribution.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ----------------------------------------------------------------------------
 */
/*-----------------------------------------------------------------------------
 *  File Name           : main.c
 *  Object              : main file
 *  Creation            : FDy   10-Nov-2006
 *-----------------------------------------------------------------------------
 */

/* Include Standard files */
#include "project.h"

/* Global variables */
#define LED_A    AT91B_POWERLED
#define LED_B    AT91B_LED1
#define BUTTON_A AT91B_BP3
#define BUTTON_B AT91B_BP4

#define MCK_FREQ 99328000
#define SLOW_CLOCK 32768

#define DEBOUNCE_TIME  500

/* The following global variables, control the LED blinking */
unsigned long led_a_active = 1;
unsigned long led_b_active = 1;
volatile unsigned long jiffies = 0;

static void configure_pit(void);
static void configure_buttons(void);
static void configure_leds(void);
static void configure_tc(void);
static void configure_dbgu(void);


/*-----------------------------------------------------------------------------
 * Function Name       : pabt_handler
 * Object              : Prefetch Abort Handler
 *-----------------------------------------------------------------------------*/
void pabt_handler(void)
{
	dbgu_print_ascii("-F- Prefetch abort\n\r");
}

/*-----------------------------------------------------------------------------
 * Function Name       : dabt_handler
 * Object              : Data Abort Handler
 *-----------------------------------------------------------------------------*/
void dabt_handler(void)
{
	dbgu_print_ascii("-F- Data abort\n\r");
}

/*-----------------------------------------------------------------------------
 * Function Name       : pitc_handler
 * Object              : Handler for PITC interrupt
 *-----------------------------------------------------------------------------*/
void pitc_handler(void)
{
  unsigned long pivr = 0;
  unsigned long pisr = 0;

  /* Read the PISR */
  pisr = AT91C_BASE_PITC->PITC_PISR & AT91C_PITC_PITS;
  if (pisr != 0) {
    /* Read the PIVR. It acknowledges the IT */
    pivr = AT91C_BASE_PITC->PITC_PIVR;

    /* Add to jiffies PICNT: the number of occurrences of periodic intervals  */
    /* since the last read of PIT_PIVR */
    jiffies += (pivr >> 20);
  }
}


/*-----------------------------------------------------------------------------
 * Function Name       : configure_pit
 * Object              : Configure priodic interval timer
 *-----------------------------------------------------------------------------*/
static void configure_pit(void)
{
  volatile unsigned long pimr = 0;

  /* Configure a resolution of 1 ms */
  AT91C_BASE_PITC->PITC_PIMR = MCK_FREQ / (16 * 1000) - 1;

  /* Enable interrupts */
  /* Disable the interrupt on the interrupt controller */
  AT91C_BASE_AIC->AIC_IDCR = (1 << AT91C_ID_SYS);

  /* Save the interrupt handler routine pointer and the interrupt priority */
  AT91C_BASE_AIC->AIC_SVR[AT91C_ID_SYS] = (unsigned long) pitc_handler;
  /* Store the Source Mode Register */
  AT91C_BASE_AIC->AIC_SMR[AT91C_ID_SYS] = AT91C_AIC_SRCTYPE_INT_LEVEL_SENSITIVE | AT91C_AIC_PRIOR_LOWEST;
  /* Clear the interrupt on the interrupt controller */
  AT91C_BASE_AIC->AIC_ICCR = (1 << AT91C_ID_SYS);

  /* Enable the interrupt on the interrupt controller */
  AT91C_BASE_AIC->AIC_IECR = (1 << AT91C_ID_SYS);

  /* Enable the interrupt on the pit */
  pimr = AT91C_BASE_PITC->PITC_PIMR;
  AT91C_BASE_PITC->PITC_PIMR = pimr | AT91C_PITC_PITIEN;

  /* Enable the pit */
  pimr = AT91C_BASE_PITC->PITC_PIMR;
  AT91C_BASE_PITC->PITC_PIMR = pimr | AT91C_PITC_PITEN;
}


/*-----------------------------------------------------------------------------
 * Function Name       : button_handler
 * Object              : Button Interrupt Service Routine (PIO A)
 *-----------------------------------------------------------------------------*/
void button_handler(void)
{
  /* Read the Interrupt Status register (It acknowledge the IT)  */
  volatile unsigned long pio_isr = AT91C_BASE_PIOA->PIO_ISR;
  volatile unsigned long pio_pdsr = AT91C_BASE_PIOA->PIO_PDSR;
  static unsigned long button_a_jiffies = 0;
  static unsigned long button_b_jiffies = 0;


  /* If the BUTTON_A has been pushed or released */
  if (pio_isr & BUTTON_A) {
    /* Enable/disable the LED A blinking when BUTTON_A is released */
    if (pio_pdsr & BUTTON_A) {
      if (jiffies - button_a_jiffies > DEBOUNCE_TIME) {
	button_a_jiffies = jiffies;
	led_a_active = !led_a_active;
      }
    }
  }
  /* If the BUTTON_B has been pushed or released */
  else if (pio_isr & BUTTON_B) {
    /* Enable/disable the LED B blinking when BUTTON_B is pushed */
    if (!(pio_pdsr & BUTTON_B)) {
      if (jiffies - button_b_jiffies > DEBOUNCE_TIME) {
	button_b_jiffies = jiffies;
	if (led_b_active) {
	  /* Disable the clock */
	  AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS;
	} else {
	  /* Clock is started */
	  AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
	  /* Counter is reset and the clock is started */
	  AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG;
	}
	led_b_active = !led_b_active;
      }
    }
  }
  /* The else should not be executed since no other PIO are enabled  */
  else { }
}


/*-----------------------------------------------------------------------------
 * Function Name       : configure_buttons
 * Object              : Configure pios to capture buttons state
 *-----------------------------------------------------------------------------*/
static void configure_buttons(void)
{
  /* Enable the periph clock for the PIO controller */
  /* This is mandatory when PIO are configured as input */
  AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_PIOA);

  /* Set the PIO line in input */
  AT91C_BASE_PIOA->PIO_ODR = (BUTTON_A | BUTTON_B);

  /* Set the PIO controller in PIO mode instead of peripheral mode */
  AT91C_BASE_PIOA->PIO_PER = (BUTTON_A | BUTTON_B);

  /* Disable the interrupt on the interrupt controller */
  AT91C_BASE_AIC->AIC_IDCR = (1 << AT91C_ID_PIOA);

  /* Save the interrupt handler routine pointer and the interrupt priority */
  AT91C_BASE_AIC->AIC_SVR[AT91C_ID_PIOA] = (unsigned long) button_handler;

  /* Store the Source Mode Register */
  AT91C_BASE_AIC->AIC_SMR[AT91C_ID_PIOA] = AT91C_AIC_SRCTYPE_INT_LEVEL_SENSITIVE | AT91C_AIC_PRIOR_LOWEST;

  /* Clear the interrupt on the interrupt controller */
  AT91C_BASE_AIC->AIC_ICCR = (1 << AT91C_ID_PIOA);

  /* Enable button interrupts generation through the PIO controller */
  AT91C_BASE_PIOA->PIO_IER = (BUTTON_A | BUTTON_B);

  /* Enable PIO interrupt in the interrupt controller */
  AT91C_BASE_AIC->AIC_IECR = (1 << AT91C_ID_PIOA);
}